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Investigation of four wave mixing & cross gain modulation in photonic transmission system
No full textMaster of Science in Microelectronic EngineeringThis thesis focuses on investigation of two nonlinear effects, four wave mixing (FWM) and cross gain modulation (XGM) in photonic transmission system. The work begins with analyzing the performance for both nonlinear effects in multiple channels of wavelength division multiplexing (WDM) transmission system. It addresses the optical transmission
system for long haul transmission. The long haul model of 16 channels RZ and NRZ over 1680 km achieved a good signal to noise ratio. The Q-factor decreases with the growth number of channels for both NRZ and RZ format. This study also examined several modulation formats in DWDM system such as RZ, NRZ and duobinary. It is observed that the Q factor degrades slower for RZ in comparison to NRZ. The duobinary has shown the most efficient format due to its nonlinear and band limitation robustness than traditional modulation formats, such as RZ and NRZ. In the observation, FWM and XGM crosstalk degrades the optical signal transmission characteristic of multiplexing signals system significantly. This could be attributed to the higher power launched into the individual channel that led to the nonlinear effects. The work is designed to optimize the performance
for the DWDM system considering the limitation imposed by the nonlinear effects. Preliminarily, in-line optical amplifiers and repeaters are noticed to enhance the system. Other approach known as unequal spacing channel allocation in multichannel transmitter is employed to overcome limitation imposes by FWM and XGM. The observation reveals out that unequal channel spacing advances the Q-factor for the system as compared to equal channel spacing. It is also clearly observed that the adoption of duobinary modulation scheme reduces the impact of FWM in DWDM system. The levels of FWM products are reduced by
around 12 dB which offer a prominent performance benefit for the system
Determination of optimized soft starter firing angle to mitigate high inrush current during motor starting using PSCAD
No full textMaster of Science in Electrical Power EngineeringStarting of an induction motor is a process that creates many challenging problems for
the motor and operations of the power system. The induction motor can be damaged,
characteristic can be changed and performance of the motor can be worsen. An
induction motor draws a high starting current and develops a high torque during the
start-up. Inrush current often causes problem such as voltage dips and sags that occur in
electrical power system associated with motor. The different motors starters available in
Malaysia market are being discussed and analyzed. It includes both conventional
electromechanical starters and power electronic drives. A comparison between the
starters found that soft starter is the most convincing because the configuration just
involves some power conductor device that control the current flow from power source
to the motor. The switch is in the form of thyristor and being connected back-to-back.
The current output can be controlled by varying the firing angle. This changing of firing
angle is managed by a firing angle control circuit. PSCAD/EMTDC software is used for
model implementation and in carrying out extensive simulation studies. Firstly, the
power source was directly connected to the induction motor and the circuit is simulated
to analyze the inrush current. The analysis of the starter is repeated by using star delta
starter and soft starter. For soft starter, the thyristor acts as a gate to control the voltage
applied to the motor. The firing angle was varied until the high current was mitigated.
This research was finally concluded that soft starter circuit is designed to be used to
mitigate inrush current
UniMAP menang ITEX Golden Award 2022, gondol emas tertinggi
No full textLink to publisher homepage at https://www.unimap.edu.my/Seramai 30 penyelidik Universiti Malaysia Perlis (UniMAP) sekali lagi melakar sejarah dan kecemerlangan apabila meraih 100 peratus pingat pada 33rd International, Invention, Innovation & Technology Exhibition (ITEX 2022)